Method for testing visual characteristics, method for determining characteristics of optical filter, optical filter, optical element set for testing visual characteristics and test image for testing visual characteristics

Abstract

A method for testing visual characteristics includes a providing step of providing a subject with a test image and a changing step of changing an optical element to be placed between the subject and the test image. The test image includes a first image area containing a color to which rod cells are sensitive, and the first image area is placed in such a manner that light coming from the first image area forms an image on a region outside a central fovea of a retina when the subject is looking at a center of the test image. The optical element set includes a plurality of first optical elements configured to transmit light of a first wavelength band to which the rod cells are sensitive within a visible light band. An optical element that the subject does not feel dazzled by the test image is specified.

What is claimed is: 
     
         1 . A method for testing visual characteristics, comprising:
 a first determining step of determining whether a first test condition is satisfied when a subject is looking at a test image through an optical element for testing; and   at least one of:
 a changing step of changing the optical element for testing to be placed between the subject and the test image from one element to another among a plurality of optical elements included in an optical element set prepared for the optical element for testing; and 
 a providing step of providing the subject with a particular image as the test image, 
   wherein the particular image includes a first image area containing a color to which rod cells of a human are sensitive, the first image area being placed on the particular image in such a manner that light coming from the first image area forms an image on a region outside a central fovea of a retina of the subject when the subject is looking at a center of the particular image,   wherein the optical element set includes a plurality of first optical elements configured to transmit light of a first wavelength band to which the rod cells are sensitive within a visible light band, the plurality of first optical elements having respective different transmittances in the first wavelength band,   wherein the plurality of first optical elements have a common upper limit of the first wavelength band, the upper limit of the first wavelength band being set between a wavelength at which an absorption spectrum of S cone cells of the human and an absorption spectrum of the rod cells intersect each other, and a wavelength at which the absorption spectrum of the rod cells and an absorption spectrum of M cone cells of the human intersect each other, and   wherein, when the method for testing visual characteristics comprises the changing step, the first determining step specifies, from among the plurality of first optical elements, a first optical element that satisfies the first test condition when the subject is looking at the test image through the first optical element placed between the subject and the test image.   
     
     
         2 . The method for testing visual characteristics according to  claim 1 ,
 wherein the first test condition is a condition that the subject does not feel dazzled by the test image when the subject is looking at the test image.   
     
     
         3 . The method for testing visual characteristics according to  claim 1 ,
 wherein, when the method for testing visual characteristics includes the changing step, and the plurality of first optical elements include more than one first optical element satisfying the first test condition, the first determining step specifies a first optical element having a highest transmittance from among the more than one first optical element satisfying the first test condition.   
     
     
         4 . The method for testing visual characteristics according to  claim 1 ,
 wherein the particular image further includes a second image area, the second image area being placed on the particular image in such a manner that light coming from the second image area forms an image on a region within the central fovea of the retina of the subject when the subject is looking at a center of the second image area,   wherein the second image area contains at least two divided areas having respective different colors,   wherein, with respect to at least one component of an R component and a G component in an RGB color space, the at least two divided areas have respective different magnitudes of the at least one component, and respective B components of the at least two divided areas have arbitrary magnitudes, and   wherein the method for testing visual characteristics further comprises a second determining step of determining whether a second test condition is satisfied when the subject is looking at the second image area.   
     
     
         5 . The method for testing visual characteristics according to  claim 4 ,
 wherein the second test condition is a condition that the subject clearly recognizes a difference in color between the at least two divided areas when the subject is looking at the second image area.   
     
     
         6 . The method for testing visual characteristics according to  claim 4 ,
 wherein the optical element set further includes:
 a plurality of second optical elements configured to transmit light of a second wavelength band to which M cells of the human are sensitive; and 
 a plurality of third optical elements configured to transmit light of a third wavelength band to which L cells of the human are sensitive, 
   wherein the plurality of second optical elements have respective different transmittances in the second wavelength band,   wherein the plurality of third optical elements have respective different transmittances in the third wavelength band, and   wherein the second determining step determines whether the second test condition is satisfied when the subject is looking at the second image area through one optical element selected from among the plurality of second optical elements and the plurality of third optical elements.   
     
     
         7 . The method for testing visual characteristics according to  claim 1 ,
 wherein the absorption spectrum of the S cone cells is an absorption spectrum of the S cone cells of the human normalized by a maximum value thereof,   wherein the absorption spectrum of the rod cells is an absorption spectrum of the rod cells of the human normalized by a maximum value thereof, and   wherein the absorption spectrum of the M cone cells is an absorption spectrum of the M cone cells of the human normalized by a maximum value thereof.   
     
     
         8 . A method for determining characteristics of optical filter including a determining step of determining transmittance, in the first wavelength band, of an optical filter used for adjusting light intensity based on transmittance, in the first wavelength band, of the first optical element, the first optical element being determined to be satisfied the first test condition in the first determining step of the method for testing visual characteristics according to  claim 1 . 
     
     
         9 . The method for determining characteristics of optical filter according to  claim 8 ,
 wherein transmittance, in the first wavelength band, of the optical filter is determined to be transmittance, in the first wavelength band, of the first optical element that satisfied the first test condition.   
     
     
         10 . The method for determining characteristics of optical filter according to  claim 6 , further including a determining step of determining at least one of:
 transmittance, in the second wavelength band, of an optical filter used for adjusting light intensity based on transmittance, in the second wavelength band, of the second optical element which is determined to be satisfied the second test condition in the second determining step of the method for testing visual characteristics including the changing step, and   transmittance, in the third wavelength band, of an optical filter used for adjusting light intensity based on transmittance, in the third wavelength band, of the third optical element which is determined to be satisfied the second test condition in the second determining step of the method for testing visual characteristics including the changing step.   
     
     
         11 . The method for determining characteristics of optical filter according to  claim 10 ,
 wherein transmittance, in the second wavelength band, of the optical filter is determined to be transmittance, in the second wavelength band, of the second optical element that satisfied the second test condition when the second optical element that satisfied the second test condition is determined in the second determining step, and   wherein transmittance, in the third wavelength band, of the optical filter is determined to be transmittance, in the third wavelength band, of the second third element that satisfied the second test condition when the third optical element that satisfied the second test condition is determined in the second determining step.   
     
     
         12 . An optical filter, transmittance in the first wavelength band of the optical filter being set to transmittance, in the first wavelength band, determined by the method for testing visual characteristics according to  claim 8 . 
     
     
         13 . An optical filter,
 wherein, when transmittance in the second wavelength band is determined by the method for testing visual characteristics according to  claim 10 , transmittance in the second wavelength band of the optical filter is set to the determined transmittance in the second wavelength band, and   wherein, when transmittance in the third wavelength band is determined by the method for testing visual characteristics according to  claim 10 , transmittance in the third wavelength band of the optical filter is set to the determined transmittance in the third wavelength band.   
     
     
         14 . An optical element set for testing visual characteristics including a plurality of optical elements,
 wherein the optical element set includes a plurality of first optical elements configured to transmit light of a first wavelength band to which rod cells of a human are sensitive within a visible light band, the plurality of first optical elements having respective different transmittances in the first wavelength band, and   wherein the plurality of first optical elements have a common upper limit of the first wavelength band, the upper limit of the first wavelength band being set between a wavelength X S-Rod  at which an absorption spectrum of S cone cells of the human and an absorption spectrum of the rod cells intersect each other, and a wavelength X Rod-M  at which an absorption spectrum of the rod cells and an absorption spectrum of M cone cells of the human intersect each other.   
     
     
         15 . The optical element set for testing visual characteristics according to  claim 14 ,
 wherein, when difference between the wavelength X Rod-M  at which the absorption spectrum of the S cone cells and the absorption spectrum of the rod cells intersect each other and a wavelength P Rod  at which the rod cells have a highest sensitivity is set to Δ, the upper limit of the first wavelength band is set within a wavelength range P Rod ±Δ.   
     
     
         16 . The optical element set for testing visual characteristics according to  claim 14 ,
 wherein the upper limit of the first wavelength band is set to the wavelength P Rod  at which the rod cells have a highest sensitivity.   
     
     
         17 . The optical element set for testing visual characteristics according to  claim 14 ,
 wherein the upper limit of the first wavelength band is set to about 498 nm.   
     
     
         18 . The optical element set for testing visual characteristics according to  claim 14 ,
 wherein the plurality of first optical elements have a common lower limit of the first wavelength band, the lower limit of the first wavelength band being set to a wavelength P S  at which the S cone cells have a highest sensitivity.   
     
     
         19 . The optical element set for testing visual characteristics according to  claim 14 ,
 wherein the plurality of first optical elements have a common lower limit of the first wavelength band, the lower limit of the first wavelength band being set to about 420 nm.   
     
     
         20 . The optical element set for testing visual characteristics according to  claim 14 ,
 wherein the absorption spectrum of the S cone cells is an absorption spectrum of the S cone cells of the human normalized by a maximum value thereof,   wherein the absorption spectrum of the rod cells is an absorption spectrum of the rod cells of the human normalized by a maximum value thereof, and   wherein the absorption spectrum of the M cone cells is an absorption spectrum of the M cone cells of the human normalized by a maximum value thereof.   
     
     
         21 . The optical element set for testing visual characteristics according to  claim 14 ,
 wherein the optical element set includes a plurality of second optical elements and a plurality of third optical elements, the plurality of second optical elements being configured to transmit light of a second wavelength band to which M cells of the human are sensitive, the plurality of third optical elements being configured to transmit light of a third wavelength band to which L cells of the human are sensitive,   wherein the plurality of second optical elements have respective different transmittances in the second wavelength band, and   wherein the plurality of third optical elements have respective different transmittances in the third wavelength band.   
     
     
         22 . The optical element set for testing visual characteristics according to  claim 21 ,
 wherein the plurality of second optical elements have a common upper limit of the second wavelength band, the upper limit of the second wavelength band being set to a wavelength X M-L  at which an absorption spectrum of the M cone cells and an absorption spectrum of the L cone cells intersect each other.   
     
     
         23 . The optical element set for testing visual characteristics according to  claim 22 ,
 wherein the absorption spectrum of the M cone cells is an absorption spectrum of the M cone cells of the human normalized by a maximum value thereof, and   wherein the absorption spectrum of the L cone cells is an absorption spectrum of the L cone cells of the human normalized by a maximum value thereof.   
     
     
         24 . The optical element set for testing visual characteristics according to  claim 21 ,
 wherein the plurality of second optical elements have a common upper limit of the second wavelength band, the upper limit of the second wavelength band being set to about 548 nm.   
     
     
         25 . The optical element set for testing visual characteristics according to  claim 21 ,
 wherein the plurality of second optical elements have a common upper limit of the second wavelength band, the upper limit of the second wavelength band being set to a wavelength P Pho  at which a photopic vision of a human has a highest sensitivity.   
     
     
         26 . The optical element set for testing visual characteristics according to  claim 21 ,
 wherein the plurality of second optical elements have a common lower limit of the second wavelength band, the lower limit of the second wavelength band being set between a wavelength P Rod  at which the rod cells have a highest sensitivity and a wavelength X Rod-M  at which an absorption spectrum of the rod cells and an absorption spectrum of the M cone cells intersect each other.   
     
     
         27 . The optical element set for testing visual characteristics according to  claim 26 ,
 wherein the lower limit of the second wavelength band is set to the wavelength P Rod  at which the rod cells have a highest sensitivity.   
     
     
         28 . The optical element set for testing visual characteristics according to  claim 26 ,
 wherein the lower limit of the second wavelength band is set to about 498 nm.   
     
     
         29 . The optical element set for testing visual characteristics according to  claim 26 ,
 wherein the lower limit of the second wavelength band is set to the wavelength X Rod-M  at which an absorption spectrum of the rod cells and an absorption spectrum of the M cone cells intersect each other.   
     
     
         30 . The optical element set for testing visual characteristics according to  claim 26 ,
 wherein the lower limit of the second wavelength band is set to about 515 nm.   
     
     
         31 . The optical element set for testing visual characteristics according to  claim 21 ,
 wherein the plurality of third optical elements have a common lower limit of the third wavelength band, the lower limit of the third wavelength band being set to a wavelength X M-L  at which an absorption spectrum of the M cone cells and an absorption spectrum of the L cone cells intersect each other.   
     
     
         32 . The optical element set for testing visual characteristics according to  claim 31 ,
 wherein the absorption spectrum of the M cone cells is an absorption spectrum of the M cone cells of the human normalized by a maximum value thereof, and   wherein the absorption spectrum of the L cone cells is an absorption spectrum of the L cone cells of the human normalized by a maximum value thereof.   
     
     
         33 . The optical element set for testing visual characteristics according to  claim 31 ,
 wherein the lower limit of the third wavelength band is set to about 548 nm.   
     
     
         34 . The optical element set for testing visual characteristics according to  claim 21 ,
 wherein the plurality of third optical elements have a common lower limit of the third wavelength band, the lower limit of the third wavelength band being set to a wavelength P Pho  at which a photopic vision of a human has a highest sensitivity.   
     
     
         35 . A test image for testing visual characteristics, including a first image area including a color to which rod cells of a human are sensitive, the first image area being placed in such a manner that light coming from the first image area forms an image on a region outside a central fovea of a retina of a subject when the subject is looking at a center of the test image. 
     
     
         36 . The test image for testing visual characteristics according to  claim 35 ,
 wherein a color of the first image area is achromatic.   
     
     
         37 . The test image for testing visual characteristics according to  claim 35 , including a second image area, the second image area being placed in such a manner that light coming from the second image area forms an image on a region within the central fovea of the retina of the subject when the subject is looking at a center of the second image area,
 wherein the second image area contains at least two divided areas having colors different from each other, and   wherein at least one of a magnitude of an R component and a magnitude a G component in RGB color space are different among the at least two divided areas, and magnitudes of B components of the at least two divided areas are arbitrary values, respectively.   
     
     
         38 . The test image for testing visual characteristics according to  claim 37 ,
 wherein a size of the second image area is set in such a manner that the second image area is positioned within a viewing angle of the subject of 2 degrees when the subject is looking at a center of the second image area.   
     
     
         39 . The test image for testing visual characteristics according to  claim 37 ,
 wherein the first image area is:
 placed around the second image area; and 
 placed, on the test image, from outer periphery of the second image area to a position corresponding to a viewing angle of 40 degrees of the subject when the subject is looking at the second image area. 
   
     
     
         40 . An optical element set for testing visual characteristics, including a plurality of optical elements,
 wherein the optical element set includes a plurality of first optical elements configured to transmit light of a first wavelength band within a visible light band, the plurality of first optical elements having respective different transmittances in the first wavelength band, and   wherein the plurality of first optical elements have a common upper limit of the first wavelength band, the upper limit of the first wavelength band being set between about 453 nm and about 515 nm.   
     
     
         41 . The optical element set for testing visual characteristics according to  claim 40 ,
 wherein the plurality of first optical elements have a common lower limit of the first wavelength band, the lower limit of the first wavelength band being set to about 420 nm.   
     
     
         42 . The optical element set for testing visual characteristics according to  claim 40 ,
 wherein the optical element set includes a plurality of second optical elements and a plurality of third optical elements, the plurality of second optical elements being configured to transmit light of a second wavelength band to which M cells of the human are sensitive, the plurality of third optical elements being configured to transmit light of a third wavelength band to which L cells of the human are sensitive,   wherein the plurality of second optical elements have respective different transmittance in the second wavelength band, and   wherein the plurality of third optical elements have respective different transmittance in the third wavelength band.   
     
     
         43 . The optical element set for testing visual characteristics according to  claim 42 ,
 wherein the plurality of second optical elements have a common upper limit of the second wavelength band, the upper limit of the second wavelength band being set between about 548 nm and about 570 nm, and   wherein the plurality of second optical elements have a common lower limit of the second wavelength band, the lower limit of the second wavelength band being set between about 498 nm and about 515 nm.   
     
     
         44 . The optical element set for testing visual characteristics according to  claim 42 ,
 wherein the plurality of third optical elements have a common lower limit of the third wavelength band, the lower limit of the third wavelength band being set between about 548 nm and about 570 nm.   
     
     
         45 . An optical filter configured to change a spectrum of light transmit therethrough, the optical filter being configured to change intensity of light of a first wavelength band within a visible light band, the first wavelength band being a wavelength band to which rod cells of a human are sensitive,
 wherein the first wavelength band includes a wavelength P S  at which S cone cells of the human have a highest sensitivity and a wavelength X S-Rod  at which an absorption spectrum of S cone cells of the human and an absorption spectrum of the rod cells intersect each other, and   wherein a wavelength characteristic of transmittance of optical filter is uniform in the first wavelength band.   
     
     
         46 . The optical filter according to  claim 45 ,
 wherein an upper limit of the first wavelength band is set between a wavelength X S-Rod  at which an absorption spectrum of the S cone cells and an absorption spectrum of the rod cells intersect each other, and a wavelength X Rod-M  at which an absorption spectrum of the rod cells and an absorption spectrum of M cone cells of the human intersect each other.   
     
     
         47 . The optical filter according to  claim 45 ,
 wherein, when difference between the wavelength X Rod-M  at which the absorption spectrum of the S cone cells and the absorption spectrum of the rod cells intersect each other and a wavelength P Rod  at which the rod cells have a highest sensitivity is set to Δ, the upper limit of the first wavelength band is set within a wavelength range P Rod ±Δ.   
     
     
         48 . The optical filter according to  claim 46 ,
 wherein the upper limit of the first wavelength band is set to the wavelength P Rod  at which the rod cells have a highest sensitivity.   
     
     
         49 . The optical filter according to  claim 46 ,
 wherein the upper limit of the first wavelength band is set to about 498 nm.   
     
     
         50 . The optical filter according to  claim 45 ,
 wherein a lower limit of the first wavelength band is set to a wavelength P S  at which the S cone cells have a highest sensitivity.   
     
     
         51 . The optical filter according to  claim 45 ,
 wherein a lower limit of the first wavelength band is set to about 420 nm.   
     
     
         52 . The optical filter according to  claim 45 ,
 wherein the absorption spectrum of the S cone cells is an absorption spectrum of the S cone cells of the human normalized by a maximum value thereof,   wherein the absorption spectrum of the rod cells is an absorption spectrum of the rod cells of the human normalized by a maximum value thereof, and   wherein the absorption spectrum of the M cone cells is an absorption spectrum of the M cone cells of the human normalized by a maximum value thereof.   
     
     
         53 . The optical filter according to  claim 45 ,
 wherein the optical filter is configured to:
 correct visual characteristics of a subject, and 
 change intensity of light of the first wavelength band based on the visual characteristics of the first wavelength band of the subject. 
   
     
     
         54 . The optical filter according to  claim 45 ,
 wherein the optical filter is further configured to:
 change intensity of light of a second wavelength band within a visible light band, the second wavelength band being a wavelength band to which M cone cells of a human are sensitive; and 
 change intensity of light of a third wavelength band within a visible light band, the third wavelength band being a wavelength band to which L cone cells of a human are sensitive. 
   
     
     
         55 . The optical filter according to  claim 54 ,
 wherein an upper limit of the second wavelength band being set to a wavelength X M-L  at which an absorption spectrum of the M cone cells and an absorption spectrum of the L cone cells intersect each other.   
     
     
         56 . The optical filter according to  claim 55 ,
 wherein the absorption spectrum of the M cone cells is an absorption spectrum of the M cone cells of the human normalized by a maximum value thereof, and   wherein the absorption spectrum of the L cone cells is an absorption spectrum of the L cone cells of the human normalized by a maximum value thereof.   
     
     
         57 . The optical filter according to  claim 54 ,
 wherein an upper limit of the second wavelength band being set to about 548 nm.   
     
     
         58 . The optical filter according to  claim 54 ,
 wherein an upper limit of the second wavelength band being set to a wavelength P Pho  at which a photopic vision of a human has a highest sensitivity.   
     
     
         59 . The optical filter according to  claim 54 ,
 wherein a lower limit of the second wavelength band being set between a wavelength P Rod  at which the rod cells have a highest sensitivity and a wavelength X Rod-M  at which an absorption spectrum of the rod cells and an absorption spectrum of the M cone cells intersect each other.   
     
     
         60 . The optical filter according to  claim 59 ,
 wherein the lower limit of the second wavelength band is set to the wavelength P Rod  at which the rod cells have a highest sensitivity.   
     
     
         61 . The optical filter according to  claim 59 ,
 wherein the lower limit of the second wavelength band is set to about 498 nm.   
     
     
         62 . The optical filter according to  claim 59 ,
 wherein the lower limit of the second wavelength band is set to the wavelength X Rod-M  at which an absorption spectrum of the rod cells and an absorption spectrum of the M cone cells intersect each other.   
     
     
         63 . The optical filter according to  claim 59 ,
 wherein the lower limit of the second wavelength band is set to about 515 nm.   
     
     
         64 . The optical filter according to  claim 54 ,
 wherein a lower limit of the third wavelength band being set to a wavelength X M-L  at which an absorption spectrum of the M cone cells and an absorption spectrum of the L cone cells intersect each other.   
     
     
         65 . The optical filter according to  claim 64 ,
 wherein the absorption spectrum of the M cone cells is an absorption spectrum of the M cone cells of the human normalized by a maximum value thereof, and   wherein the absorption spectrum of the L cone cells is an absorption spectrum of the L cone cells of the human normalized by a maximum value thereof.   
     
     
         66 . The optical filter according to  claim 64 ,
 wherein the lower limit of the third wavelength band is set to about 548 nm.   
     
     
         67 . The optical filter according to  claim 54 ,
 wherein the plurality of third optical elements have a common lower limit of the third wavelength band, the lower limit of the third wavelength band being set to a wavelength P Pho  at which a photopic vision of a human has a highest sensitivity.   
     
     
         68 . The optical filter according to  claim 54 , further configured to:
 change intensity of light of the second wavelength band based on the visual characteristics of the second wavelength band of the subject; and   change intensity of light of the third wavelength band based on the visual characteristics of the third wavelength band of the subject.